Holding structure of hose clamp

ABSTRACT

A hose clamp is mounted on a fit-on portion of a hose such that a clamp band in expanded state enters in an annular clamp mounting portion and an anti-rotation engaging portion is located in a engaging holder portion. The clamp band is diametrically contracted and is tightened to the clamp mounting portion so as not to lower sealing property between the hose and a pipe.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a holding structure of a hose clamp for positioning and holding the hose clamp on an outer periphery of an end portion of a hose. The hose clamp is used, for example, for connection of a fuel hose and a pipe in a motor vehicle.

2. Description of the Related Art

In a fuel piping of a motor vehicle, for example, in order to communicate between pipes, used is a fuel hose made of rubber or elastomer, including a gasoline fuel impermeable layer. A gasoline fuel path is formed between the pipes by fitting each end portion of the fuel hose to an outer periphery of the pipe.

In order to prevent leakage of gasoline fuel at a joint region between the fuel hose and the pipe, a seal ring is disposed in an inner periphery of the fuel hose for providing a seal therebetween. And, in order to prevent the fuel hose from being detached from the pipe, the fuel hose is tightly fitted to an outer periphery of the pipe. However, different from the case of a resin tube, sufficient securing strength with respect to the pipe cannot be expected for the fuel hose itself that is made of rubber or elastomer. So, in a connecting structure typically employed, a hose clamp is fitted on an outer periphery of an end portion of the fuel hose, and the fuel hose is tightened and secured to the pipe by the hose clamp (for example, Patent Document 1).

A hose clamp for firmly securing the fuel hose to the pipe comprises an annular clamp body, and a operating portion for diametrically contracting and expanding the clamp body. The operating portion is, for example, in a form of an operation screw. When this hose clamp is used, the clamp body in diametrically expanded state is preparedly fitted on a clamp mounting portion of an end portion of the hose while being positioned in a longitudinal direction of the hose, and then, the fuel hose with the hose clamp is fitted to the pipe. After that, the clamp body is diametrically contracted, for example, by rotating the operation screw with an electric driver or air driver, to tighten the fuel hose to the pipe. In this manner, connecting work may be carried out relatively easily.

Meanwhile, for example, in the hose clamp with an operation screw, it is necessary to turn the hose clamp on the outer periphery of the end portion of the hose to locate the operation screw in a predetermined circumferential position when the operation screw is rotated, or to hold the hose clamp nonrotationally or non-turnably while the clamp body is diametrically contracted by rotating the operation screw. Thus, basically, connecting work requires both hands. However, in many cases, connecting work of the fuel hose and the pipe is done in a narrow engine compartment where parts are tightly packed and it is not allowed to do connecting work with using both hands freely. So, it bothers considerably an operator to tighten the hose clamp.

As for technique to eliminate such inconvenience, for example, Patent Document 2 discloses a holding structure of a hose clamp where a jut jutting in a longitudinal direction of a hose is provided on a clamp body, close to an operation screw, and a cutout is formed in an outer periphery of an end portion of the hose on a longitudinal inner end for receiving the jut. This allows to position the hose clamp in a circumferential direction with respect to the hose.

[Patent Document 1] JP-A, 2003-314759

[Patent Document 2] JP-A, 4-194486

By the way, when the operation screw is rotated to diametrically contract the clamp body, both end portions of the clamp body relatively move in circumferentially opposite directions, and an overlapped region of the both end portions become longer gradually. So, in a holding structure where an anti-rotation engaging portion such as a protruding portion protruding in the longitudinal direction of the hose is formed on the clamp body, when the hose is tightened to the pipe by diametrically contracting the clamp body, the anti-rotation engaging portion tends to move so as to be displaced in the circumferential direction, and, for example, the anti-rotation engaging portion is pressed against a side wall of the cutout that receives the anti-rotation engaging portion. And, for example, when the side wall of the cutout is pressed firmly by the anti-rotation engaging portion, a portion of the hose close to the side wall or an end portion of the hose is deformed nonuniformly in a pressed direction, for example, radially outwardly. This deformation is caused around the cutout in the hose or the end portion of the hose, namely, on a longitudinally inner end with respect to the clamp mounting portion. Unfortunately, in many cases, a seal ring is disposed on the longitudinally inner end with respect to the clamp mounting portion.

So, there is a fear that sealing property of the seal ring is partly lowered due to deformation in the hose or the end portion of the hose when the clamp body is diametrically contracted. As a result, tightening of the hose clamp could not secure sufficient sealing property between the hose and the pipe. By the way, Patent Document 2 discloses that a holding structure is constructed in the clamp mounting portion of the end portion of the hose. However, even in this construction, there is a fear that the end portion of the hose is subject to deformation that could result in lowered sealing property when the clamp body is diametrically contracted.

Under the circumstances described above, it is an object of the present invention to provide a holding structure of a hose clamp where the hose clamp can be positioned and held in a circumferential direction with respect to a hose, without fear that sealing property between the hose and the pipe is not damaged.

SUMMARY OF THE INVENTION

In order to achieve a foregoing object, according to the present invention, there is provided a novel holding structure of a hose clamp. In the novel holding structure of the hose clamp, the hose clamp has an annular clamp body to be fitted on a clamp mounting portion of an end portion of a hose, and. for example, the clamp body is configured so as to tighten the clamp mounting portion by diametrically contracting. The holding structure comprises an anti-rotation engaging portion formed on the clamp body, and an engaging holder portion provided on the hose. The engaging holder portion engages with the anti-rotation engaging portion in a circumferential direction when the clamp body is fitted on the clamp mounting portion, and thereby the hose clamp (for example, the hose clamp rotatable with respect to the clamp mounting portion) is positioned and held circumferentially with respect to the hose. Such engaging holder portion is provided on an end edge portion of the hose, for example, on an end portion of a longitudinally outer end of the hose with respect to the clamp mounting portion. Here, the engaging holder portion is provided, for example, on a longitudinally outer end of the clamp mounting portion or a longitudinally outer end with respect to the clamp mounting portion. The hose clamp may be provided with an operation screw for diametrically contracting or expanding the clamp body, and the anti-rotation engaging portion may be provided on the clamp body, for example, near the operation screw. And, the anti-rotation engaging portion may be provided, for example, in a clamp housing formed in the clamp body for receiving the operation screw. The operation screw may be provided on a circumferential end portion (for example, one circumferential end portion) of the clamp body, for example, so as to extend in a tangential direction of the clamp body. Further, the anti-rotation engaging portion may be designed so as to protrude from the clamp body in a longitudinal direction of the hose, toward an end edge of the hose, or longitudinally outward. In an inner periphery of an end portion of the hose, a seal member or a sealing portion is provided. The seal member or the sealing portion may be arranged on a longitudinally inner end with respect to the clamp mounting portion. In this construction, when the anti-rotation engaging portion is displaced in a circumferential direction and contacts firmly against the engaging holder portion, the hose is deformed only in a limited region of the hose, namely an end edge, end edge portion or end edge region of the hose or of an end portion of the hose. This arrangement does prevent that a sealing property of the seal member such as seal ring disposed in the inner periphery of the hose or of the sealing portion is partly lowered. The clamp mounting portion is located, for example, between the engaging holder portion or the end edge portion on a longitudinally outer end of the hose and a sealing region (a region where the seal member or the sealing portion is arranged) on a longitudinally inner end thereof.

The engaging holder portion may be in a form of a cutout or recess (including a cut portion or a cut region) formed in the end edge portion of the hose. This construction prevents formation of a diametrically long projecting portion on the hose or the end portion of the hose with the engaging holder portion. A beam or spool, or an opening preventing beam or spool (cord or strip member) bridges in the cutout, for example, integrally bridges in the cutout (or recess). When the cutout is hard to open, deformation of the end edge portion of the hose can be effectively prevented. The beam is arranged, for example, within the cutout.

When the clamp body tightens the clamp mounting portion, for example, the clamp mounting portion gets slightly longer in an axial direction or a longitudinal direction, and the end edge portion is moved in the longitudinal direction. So, when the clamp body is fitted on the clamp mounting portion and a portion of the anti-rotation engaging portion engaging with the cutout is close to the beam, diametrically contracting the clamp body might contact the anti-rotation engaging portion with the beam and thereby the beam might be damaged. In order to prevent such inconvenience, preferably the beam is provided in a longitudinally inner end of the cutout, and the anti-rotation engaging portion is designed to engage with a longitudinally outer end of the cutout when the clamp body is fitted on the clamp mounting portion. Or the anti-rotation engaging portion is designed not to contact with the beam when the clamp body is diametrically contracted so as to tighten the clamp mounting portion.

A protruding portion protruding in a longitudinal direction may be formed on an end edge of the hose, and the engaging holder portion may be formed in the protruding portion. In this arrangement, deformation caused on the hose or the end portion of the hose while diametrically contracted can be limited within the protruding portion or mostly within the protruding portion.

In another holding structure of a hose clamp according to the present invention, the hose clamp also has an annular clamp body to be fitted on a clamp mounting portion of an end portion of a hose, and, for example, the clamp body is also configured so as to tighten the clamp mounting portion by diametrically contracting. The another holding structure also comprises an anti-rotation engaging portion formed on the clamp body, and an engaging holder portion provided on the hose so as to engage with the anti-rotation engaging portion in a circumferential direction when the clamp body is fitted on the clamp mounting portion. The clamp body has one circumferential end portion and the other circumferential end portion, and is provided with an operation screw on the other circumferential end portion for diametrically contracting and expanding the clamp body by engaging with the one circumferential end portion or one circumferential end area (an area of the one circumferential end portion and a portion adjacent to the one circumferential end portion). The operation screw is arranged so as to extend or lie in a tangential direction or generally in the tangential direction of the clamp body. The engaging holder portion includes a pair of side portions in circumferentially spaced, face-to-face relation to each other. The engaging holder portion is formed so as to position the anti-rotation engaging portion in the circumferential direction while receiving the anti-rotation engaging portion movably in the circumferential direction between the pair of the side portions. And, a circumferential distance between the pair of the side portions is set so as to locate the anti-rotation engaging portion midway between the pair of the side portions when the clamp body is diametrically contracted to tighten the clamp mounting portion by rotating the operation screw. The operation screw may be formed to have a head and a leading end portion (for example, a leading end portion of a threaded portion) and may be arranged with the head being located on a circumferential center side of the clamp body (a longitudinal center side of the clamp body in its flattened state) with respect to the leading end portion. And, the anti-rotation engaging portion may be formed on one circumferential side portion of the clamp body, for example, a portion of the clamp body on a side toward the one circumferential end portion with respect to a circumferential center or a circumferential center portion and that is displaced in a direction toward the operation screw when the clamp body is diametrically contracted, or a portion defined by the one circumferential end portion and the portion of the clamp body that is displaced in the direction toward the operation screw when the clamp body is diametrically contracted. Circumferential engagement between the engaging holder portion (more specifically, the side portions) and the anti-rotation engaging portion (for example, protruding from the clamp body in an opposite direction of an end edge of the hose), or circumferential-positioning function of the engaging holder portion with respect to the anti-rotation engaging portion serves to position and hold the hose clamp (for example, a rotatable hose clamp) in the circumferential direction with respect to the hose. The engaging holder portion is provided, for example, on a longitudinally inner end of the clamp mounting portion or on a longitudinally inner end with respect to the clamp mounting portion. The operation screw is disposed, for example, along the clamp body. In this arrangement, the clamp body is loosely fitted on the clamp mounting portion so as to turn in the circumferential direction. Therefore, when a driver (for example, an electric driver) is pressed onto the head (which is provided on an end opposite to the leading end portion) to diametrically contract the clamp body and tighten the clamp mounting portion, even if the anti-rotation engaging portion initially does not abut the side portion (for example, side wall) located downstream in terms of a direction of turning force applied to the clamp body by the driver, the anti-rotation engaging portion is pressed against the downstream side portion. Then, the operation screw is rotated, and the clamp body is diametrically contracted. Here, if the clamp body does not turn, the anti-rotation engaging portion is moved toward the operation screw, and displaced so as to be away from the downstream side portion or the side portion against which the anti-rotation engaging portion has been pressed. But, in fact, since the clamp body can still turn or rotate in the circumferential direction, the anti-rotation engaging portion is continuously pressed against that side portion (the downstream side portion) under a pressure exerted by the driver. However, when the clamp body is diametrically contracted to start tightening the clamp mounting portion, the clamp body is not allowed or is almost not allowed to turn in the circumferential direction even under the pressure exerted by the driver. Therefore, as the operation screw is further rotated, the anti-rotation engaging portion is displaced and moved so as to be away from the downstream side portion against which the anti-rotation engaging portion is pressed. So, the anti-rotation engaging portion is constructed not to be allowed to abut the side portion located opposite to that side portion against which the anti-rotation engaging portion has been pressed or the side portion located upstream in terms of the direction of turning force applied to the clamp body by the driver, until operation of diametrically contracting the clamp body is completed. In this construction, the hose can be effectively prevented from deformation caused during fixedly securing the hose clamp on the clamp mounting portion. Here, the anti-rotation engaging portion is located midway between the pair of the side portions, namely the anti-rotation engaging portion abuts or is pressed against neither of the side portions, when operation of diametrically contracting the hose clamp is completed.

The clamp body may be in a form of a clamp band, and the clamp band may be constructed so as to be diametrically contracted or expanded by adjusting an overlapped length or a crossover length of circumferentially opposite end portions or of the one circumferential end area and the other circumferential end area (an area of the other circumferential end portion and a portion adjacent to the other circumferential end portion) thereof. The clamp band may be made from a metal strip or a metal wire (for example, two wires arranged in substantially parallel spaced relation).

By the way, it is considerably difficult to diametrically contract the clamp body reasonably by rotating the operation screw properly. When the clamp body is diametrically contracted in greater degree, it is feared that an end portion of the hose is damaged. On the other hand, when the clamp body is diametrically contracted in less degree, securing condition or sealing property between the hose and the pipe becomes insufficient. So, preferably, the clamp band is provided on the other circumferential side portion (a portion of the clamp band on a side toward the other circumferential end portion with respect to a circumferential center or a circumferential center portion, or a portion opposite to the one circumferential side portion), the other circumferential end area or a circumferential center side of the other circumferential side portion with respect to the operation screw, with a stopper or a marking for preventing the clamp band from being diametrically overcontracted. The clamp band is to be diametrically contracted to tighten the clamp mounting portion properly by rotating the operation screw until one circumferential edge of the clamp band abuts the stopper or reaches a position of the marking. Here, a circumferential distance between the pair of the side portions is set so as not to allow the anti-rotation engaging portion to abut the side portion located opposite to that side portion against which the anti-rotation engaging portion has been pressed or the side portion located upstream when the one circumferential edge of the clamp band abuts the stopper or reaches the position of the marking. In other words, the anti-rotation engaging portion is located midway between the pair of side portions when the one circumferential edge of the clamp band abuts the stopper or reaches the position of the marking. Such construction does not allow the anti-rotation engaging portion to abut the side portion located opposite to that side portion against which the anti-rotation engaging portion has been pressed or the upstream side portion when the clamp band or clamp body is diametrically contracted to tighten the clamp mounting portion by rotating the operation screw.

With the holding structure of the hose clamp according to the present invention, the hose clamp can be fitted and positioned on the hose so as not to be displaced in the circumferential direction until the hose clamp is tightened to the hose. And, tightening of the hose can be completed without damaging a sealing property between the hose and the pipe.

Now, the preferred embodiments of the present invention will be described in detail with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hose for constructing a holding structure of a hose clamp according to the present invention.

FIG. 2 is a perspective view showing a hose with clamp where the hose clamp is fitted to the hose.

FIG. 3 is a side view of the hose with clamp.

FIG. 4 is an enlarged view showing a region of an engaging holder portion.

FIG. 5 is a side view showing a state of the hose with clamp after the hose clamp is tightened to the hose.

FIG. 6 is a plane view showing the state of the hose with clamp after the hose clamp is tightened to the hose.

FIG. 7 is a perspective view of another hose for constructing another holding structure of a hose clamp according to the present invention.

FIG. 8 is a perspective view showing another hose with clamp where the another hose clamp is fitted to the another hose.

FIG. 9 is a side view of the another hose with clamp.

FIG. 10(a) is a view for explaining motion of an anti-rotation engaging portion when the another hose clamp is diametrically contracted, and showing a state of the anti-rotation engaging portion just before the another hose is tightened.

FIG. 10(b) is a view for explaining motion of an anti-rotation engaging portion when the another hose clamp is diametrically contracted, and showing a state of the anti-rotation engaging portion after the another hose is tightened.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A hose 1 shown in FIGS. 1 and 2 is adapted for fuel piping around a fuel tank in a motor vehicle. The hose 1 has a gasoline fuel impermeable hose body 3 and a fit-on portion 5 formed integrally on an end portion of the hose body 3. The hose body 3 is mainly constructed of a rubber layer. A hose clamp 7 is mounted on the fit-on portion 5 of thus constructed hose 1, and thereby a hose with clamp 9 is obtained.

The fit-on portion 5 of the hose 1 has a clamp portion or to-be clamped portion 11 on a longitudinally outer end thereof, and a sealing portion 13 on a longitudinally inner end thereof. The clamp portion 11 has a clamp mounting portion 15 on a longitudinally inner end thereof, and an end edge portion 17 on a longitudinally outer end thereof that defines an opening edge portion. The sealing portion 13 is designed so as to be raised radially outward throughout its entire circumference, or so as to have an outer peripheral surface raised radially outward throughout its entire circumference. The sealing portion 13 includes an annular groove 19 in its inner periphery, and a seal ring 21 is fitted in the annular groove 19 (also refer to FIG. 3). The end edge portion 17 of annular shape includes a base portion 23 of half-circle (semicircle) or semiannular shape (for example, a half annular ring), and a holder formation portion 25 of semiannular shape (for example, a half annular ring) on an end opposite to the base portion 23. The end edge portion 17 has an outer radius generally equal to that of the annular clamp mounting portion 15 (a mounting outer surface 29) on the base portion 23, while having an outer radius gradually enlarging from circumferentially opposite ends of the holder formation portion 25 in a symmetrical manner on the holder formation portion 25. More specifically, on the holder formation portion 25, the end edge portion 17 has an outer surface or outer peripheral surface that gradually expands radially outward from circumferentially opposite ends of the holder formation portion 25 in the symmetrical manner. The end edge portion 17 further integrally includes a thin-walled collar portion 27 slightly projecting radially outward on an outer periphery of a longitudinally inner edge portion of the base portion 23. Circumferentially opposite edges of the collar portion 27 reach outer peripheries of the circumferentially opposite ends of the holder formation portion 25. So, the clamp mounting portion 15 includes an annularly grooved mounting outer surface 29 between the end edge portion 17 and the sealing portion 13. A protruding height of the holder formation portion 25 with respect to the clamp mounting portion 15 or the mounting outer surface 29 gradually increases from the circumferentially opposite edges toward a circumferential center thereof Meanwhile, an inner periphery of a longitudinally outer end of the end edge portion 17 has a large diameter.

The holder formation portion 25 has a protruding portion 33 protruding longitudinally outward, increasingly from the circumferentially opposite ends toward the circumferentially center thereof, and a longitudinally outer end surface 31 of the protruding portion 33 is slightly inclined or slanted longitudinally outward, on each circumferential edge of the longitudinally outer end surface 31 adjacent to the base portion 23. A circumferentially center portion (the most projecting portion with respect to the mounting outer surface 29) of the holder formation portion 25 including the protruding portion 33, is cut out in narrow width throughout its entire length to define a engaging holder portion 37 (a radially outer end of the engaging holder portion 37 is located radially outward with respect to the mounting outer surface 29) between cut surfaces 35, 35. The engaging holder portion 37 is provided inside and integrally with an opening preventing beam (spool) 39 bridging over a cutout, so as to be located on radially outer end (for example, radially outward with respect to the mounting outer surface 29) and longitudinally inner end thereof. The beam 39 bridges between one and the other cut surfaces 35, 35 (refer to FIG. 4) along an extended line of the collar portion 27. The beam 39 is made of rubber material identical to that of the end edge portion 17. By the way, only a portion formed in the protruding portion 33 may be regarded as a engaging holder portion.

In the clamp mounting portion 15 of the hose 1, the hose clamp 7 is mounted or fitted so as to be positioned in a longitudinal direction of the hose 1. The hose clamp 7 has a clamp band (clamp body) 41, a band-carrier clamp (clamp housing) 43 provided on one circumferential end portion of the clamp band 41, an operation screw 47 received in a screw receiving portion 45 of the band-carrier clamp 43 and an anti-rotation engaging portion 49 provided integrally on the band-carrier clamp 43 so as to extend in a direction perpendicular to the operation screw 47. The clamp band 41 is flexible, and is made of metal such as stainless steel. The operation screw 47 is received in the screw receiving portion 45 so as to turn free and extend in a tangential direction of the clamp band 41. The clamp band 41 includes a number of engaging slits 51 extending in a widthwise direction thereof on the other circumferential end area thereof. The engaging slits 51 are arranged serially in a longitudinal direction (in a circumferential direction of the hose 1) of the clamp band 41. The other circumferential end area of the clamp band 41 is passed through the band-carrier clamp 43 such that the engaging slits 51 engage with a male threaded portion 53 of the operation screw 47 (the engaging slits 51 are often slightly angled with respect to a widthwise direction in order to ensure engagement or thread engagement with the male threaded portion 53). For example, an electric driver or air driver is engaged in a driver slit formed in a head 55 of the operation screw 47, and the operation screw 47 is rotated by the electric driver to allow to adjust a length of the other circumferential end area of the clamp band 41 relatively passing through the band-carrier clamp 43, thereby to adjust a diameter of the clamp band 41. The band-carrier clamp 43 may be regarded, for example, as a part of the clamp band 41.

The anti-rotation engaging portion 49 has a supporting rod 57 that extends from the band-carrier clamp 43 in a direction perpendicular to the operating screw 47, and an inserting holding portion 59 of horseshoe shape that is provided integrally on a leading end (outer end) of the supporting rod 57. The inserting holding portion 59 is connected to the leading end of the supporting rod 57 via a connecting portion 61 with its opening facing radially inward. The hose clamp 7 is fitted on the clamp mounting portion 15 so that the anti-rotation engaging portion 49 or the supporting rod 57 protrudes on a side of an end edge of the hose 1.

The hose clamp 7 is mounted or fitted on the fit-on portion 5 of the hose 1 so that the clamp band 41 in a diametrically expanded state enters or seats in the annular mounting outer surface 29 (this means that the clamp band 41 is prevented from being displaced in a longitudinal direction of the hose 1), while the inserting holding portion 59 is inserted in the engaging holder portion 37, more specifically in a longitudinally outer end of the engaging holder portion 37. In this manner, a holding structure of the hose clamp 7 is constructed. Since a width of the annular mounting outer surface 29 is slightly longer than a width of the clamp band 41, the clamp band 41 seats in the mounting outer surface 29 with a clearance in the longitudinal direction of the hose 1. And, since a width of the inserting holding portion 59 is slightly shorter than a width of the engaging holder portion 37, the inserting holding portion 59 enters in the engaging holder portion 37 with a clearance in a circumferential direction.

As well shown in FIGS. 2 and 3, the hose clamp 7 is mounted or fitted on the fit-on portion 5 of the hose 1 while the clamp band 41 enters in the annular mounting outer surface 29 and the inserting holding portion 59 is inserted in the engaging holder portion 37. Thus, the hose clamp 7 is not allowed to be displaced in the longitudinal direction or the circumferential direction of the hose 1 until the hose 1 is fitted to a pipe (and afterwards). Then, the hose 1 is fitted to the pipe 63, and the clamp band 41 is diametrically contracted by rotating the operation screw 47 of the hose clamp 7. At that time, the fit-on portion 5 or the clamp mounting portion 15 is tightened onto the pipe 63 by the clamp band 41. When the operation screw 47 is pressed by the driver, the clamp band 41 turns in the circumferential direction, and the inserting holding portion 59 abuts the cut surface 35 of the engaging holder portion 37. And, as the clamp band 41 is diametrically contracted and the clamp mounting portion 15 is tightened, the anti-rotation engaging portion 49 could be slightly displaced in the circumferential direction and the inserting holding portion 59 could be pressed against the cut surface 35 of the engaging holder portion 37. Even when this results in deformation of the end edge portion 17 such as distortion of the end edge portion 17, the deformation never adversely affects sealing function of the sealing portion 13 (as a matter of convenience for illustrating purpose, the anti-rotation engaging portion 49 is shown at a circumferential center of the engaging holder portion 37 in the drawing). Specifically, since the engaging holder portion 37 is formed in the holder formation portion 25, at the most longitudinally outward protruding part of the protruding portion 33 or at a region including the most longitudinally outward protruding part of the protruding portion 33, and the inserting holding portion 59 is designed to engage with a longitudinally outer end of the engaging holder portion 37, torsion or deformation caused by the inserting holding portion 59 is limited within the end edge portion 17 or the protruding portion 33. Meanwhile, when the hose clamp 7 is fixedly mounted to an end portion of the hose 1 by diametrically contracting the clamp band 41, the anti-rotation engaging portion 49 or the support rod 57 and the inserting holding portion 59 except for a root end of the support rod 57 are buried into the engaging holder portion 37. And, here, the support rod 57 may be constructed, for example, so as to be located slightly above the beam 39, or so as not to place a pressure or a firm pressure on the beam 39.

Meanwhile, when the clamp band 41 is diametrically contracted to tighten the clamp mounting portion 15, the clamp mounting portion 15 gets slightly longer in the longitudinal direction. And, as a result, the end edge portion 17 is moved in a longitudinally outward direction with respect to the hose clamp 7 or the inserting holding portion 59, for example, relatively (refer to arrows in FIGS. 5 and 6). At that time, a distance between the inserting holding portion 59 and the beam 39 is reduced. However, the inserting holding portion 59 is designed to remain in a region of the engaging holder portion 37 defined by or in the protruding portion 33 from before to after the clamp band 41 is diametrically contracted, while the beam 39 is located opposite to the protruding portion 33 of the engaging holder portion 37. This arrangement does not permit contact between the inserting holding portion 59 and the beam 39.

Another hose 65 shown in FIGS. 7 and 8 is also adapted for fuel piping around a fuel tank in a motor vehicle. The hose 65 has a gasoline fuel impermeable hose body 67 and a fit-on portion 69 formed integrally on an end portion of the hose body 67. The hose body 67 is mainly constructed of a rubber layer. Another hose clamp 71 is mounted and fitted on the fit-on portion 69 of thus constructed hose 65, and thereby another hose with clamp 73 is obtained.

The fit-on portion 69 of the hose 65 has a cylindrical portion 75 on a longitudinally outer end thereof, and a large diameter portion 77 on a longitudinally inner end thereof. The cylindrical portion 75 integrally has a positioning annular projection 79 on a longitudinally outer end or a longitudinally outer edge side of an outer peripheral surface thereof. The large diameter portion 77 of the fit-on portion 69 has an outer diameter equal to or generally equal to that of the positioning annular projection 79. An annular clamp mounting portion 81 is defined between the large diameter portion 77 and the positioning annular projection 79. The annular clamp mounting portion 81 includes a bottom portion that is defined by a longitudinally inner end of the outer peripheral surface of the cylindrical portion 75. The large diameter portion 77 includes an outer peripheral surface that is tapered or diametrically contracted in a tapered manner toward an outer peripheral surface of the hose body 67, on its longitudinally inner end portion. In an inner periphery of the large diameter portion 77, an annular groove 82 is formed, in which a seal ring 86 is fitted for providing a seal with respect to a pipe 84 (refer to FIG. 9).

The large diameter portion 77 is formed with an engaging recessed portion (engaging holder portion) 83 in a predetermined circumferential region of a longitudinally outer end portion of the outer peripheral surface thereof. The engaging recessed portion 83 is defined between a pair of raised portions 85, 85 that are integrally formed on the longitudinally outer end portion of the outer peripheral surface of the large diameter portion 77, in circumferentially spaced relation to each other. Each of circumferential inner surfaces of the raised portions 85, 85 defines a rotation preventing side portion or side wall. And, the circumferential inner surface of the raised portion 85 on one circumferential side (on a side in a direction (in one circumferential direction) from a circumferential center of the clamp band 87 toward one circumferential end portion 88 thereof or on a side downstream in terms of a direction from the other circumferential edge of the clamp band 87 toward the one circumferential end portion 88 thereof), namely the raised portion 85 on a right-hand side in FIG. 10 is shaped so as to be along a longitudinal direction of the hose 65, while the circumferential inner surface of the raised portion 85 on the other circumferential side (on a side in a direction (in the other circumferential direction) from a circumferential center of the clamp band 87 toward the other circumferential end portion 90 thereof or on a side downstream in terms of a direction from one circumferential edge 116 of the clamp band 87 toward the other circumferential end portion 90 thereof), namely the raised portion 85 on a left-hand side in FIG. 10 is angled so as to open toward a longitudinally inner end of the hose 65 at an angle of about 3 to 5°.

As well shown in FIG. 8, in the annular clamp mounting portion 81 of the hose 65, the hose clamp 71 is mounted or fitted so as to be positioned in a longitudinal direction of the hose 65. The hose clamp 71 has a clamp band (clamp body) 87, a band-carrier clamp (clamp housing) 89 provided on the other circumferential end portion 90 of the clamp band 87, an operation screw 93 received in a screw receiving portion 91 of the band-carrier clamp 89 and an anti-rotation engaging portion 95 provided integrally on the clamp band 87, on one circumferential side with respect to a portion diametrically opposite to the operation screw 93 or one circumferential side portion 94 of the clamp band 87. The clamp band 87 is flexible, and is made from metal such as stainless steel. The operation screw 93 is received in the screw receiving portion 91 so as to turn free and extend or lie in a tangential direction of the clamp band 87. The clamp band 87 includes a number of engaging slits 97 extending in a widthwise direction thereof on one circumferential end area 92 or one circumferential end portion 88 thereof. The engaging slits 97 are arranged serially in a longitudinal direction (in a circumferential direction of the hose 65) of the clamp band 87. One circumferential end area 92 of the clamp band 87 is passed through the band-carrier clamp 89 such that the engaging slits 97 engage with a male threaded portion 99 of the operation screw 93 (the engaging slits 97 are often slightly angled with respect to a widthwise direction in order to ensure engagement or thread engagement with the male threaded portion 99). For example, an electric driver or air driver is engaged in a driver slit formed in a head 101 of the operation screw 93, and the operation screw 93 is rotated by the electric driver to allow to adjust a length of the one circumferential end area 92 of the clamp band 87 relatively passing through the band-carrier clamp 89, thereby to adjust a diameter of the clamp band 87. The band-carrier clamp 89 may be regarded, for example, as a part of the clamp band 87. The operation screw 93 is arranged with a head 101 being located on one circumferential side (on a lower side in FIG. 10), and with the leading end portion 102 on the other circumferential side (on an upper side in FIG. 10). That is, the operation screw 93 is arranged such that, in the clamp band 87 in its flattened state, the head 101 is located closer to the longitudinal center of the clamp band 87 than the leading end portion 102. Here, the operation screw 93 is arranged such that the leading end portion 102 generally corresponds to a position of the other circumferential edge of the clamp band 87.

The anti-rotation engaging portion 95 is in a form of a plate or a thin-walled plate, provided on a circumferentially middle portion, more specifically, one circumferential side portion 94 near a portion diametrically opposite to the operation screw 93. The anti-rotation engaging portion 95 has a square or rectangular base portion 103 fixedly secured to an outer surface of the clamp band 87, and an engaging body 105 integrally formed on and bent out from an inner end of the base portion 103. The engaging body 105 includes a rise portion 107 rising or bent out radially outward from an inner end of the base portion 103, and a longitudinal portion 109 extending in a longitudinal direction of the hose 65 from an outer end of the rise portion 107. The longitudinal portion 109 except for a small region of a base end thereof defines a rotation stopper portion 111. Circumferentially opposite end portions or opposite ends of the rotation stopper portion 111 are bent outward, and thereby the rotation stopper portion 111 is formed in a horseshoe shape. The rotation stopper portion 111 is located on a longitudinally inner end with respect to the clamp band 87.

The clamp band 87 is provided with a stopper 113 for preventing the clamp band 87 from being diametrically overcontracted, on the other circumferential end area 110. A semicircular line cut 115 is made in the clamp band 87, and a portion inside the cut 115 is bent outward to form the stopper 113. The stopper 113 abuts one circumferential edge 116 of the clamp band 87 and blocks the clamp band 87 from being further diametrically contracted.

The hose clamp 71 is mounted on the fit-on portion 69 of the hose 65 so that the clamp band 87 in a diametrically expanded state enters or seats in the annular clamp mounting portion 81, while the rotation stopper portion 111 of the anti-rotation engaging portion 95 is received in the engaging recessed portion 83, and the operation screw 93 is directed, for example, with its leading end portion 102 facing in the other circumferential direction (refer to FIG. 10). In this manner, a holding structure of the another hose clamp 71 is constructed. Since a width of the annular clamp mounting portion 81 is slightly longer than a width of the clamp band 87, the clamp band 87 seats in the annular clamp mounting portion 81 with a clearance in the longitudinal direction of the hose 65. And, since a width of the rotation stopper portion 111 of the anti-rotation engaging portion 95 is one half or about one half of a width of the engaging recessed portion 83, a distance or circumferential distance between the circumferential inner surfaces of the raised portions 85 (with respect to the narrowest region thereof), the rotation stopper portion 111 is received in the engaging recessed portion 83 movably in a circumferential direction.

The hose clamp 71 is mounted or fitted on the fit-on portion 69 of the hose 65 while the clamp band 87 is located in the annular clamp mounting portion 81 and the rotation stopper portion 111 enters in the engaging recessed portion 83. Thus, the hose clamp 71 is not allowed to be displaced in the longitudinal direction or the circumferential direction of the hose 65 beyond acceptable range until the hose 65 is fitted to a pipe 84 (and afterwards) (refer to FIG. 8). Here, first, the hose 65 is fitted to the pipe 84, and an electric driver or air driver is pressed onto the head 101 of the operation screw 93 of the hose clamp 71. That way, the hose clamp 71 turns around the annular clamp mounting portion 81, for example, until the rotation stopper portion 111 abuts a circumferential inner surface of the raised portion 85 of the other circumferential end (although FIG. 8 shows that the hose clamp 71 is initially located as indicated in phantom line and then pushed by the electric driver to turn as indicated in solid line, the hose clamp 71 is not always initially located as indicated in the phantom line). And, upon diametrically contracting the clamp band 87 by rotating the operation screw 93, an inner diameter of the clamp band 87 becomes equal to an outer diameter of the clamp mounting portion 81, and the clamp band 87 starts tightening the clamp mounting portion 81 (refer to FIG. 10(a)). Then, the rotation stopper portion 111 is displaced and moved in one circumferential direction, while the operation screw 93 is displaced and moved in the other circumferential direction (refer to FIG. 10(b): As long as the clamp band 87 has an inner diameter longer than an outer diameter of the clamp mounting portion 81, even when the operation screw 93 is rotated, the rotation stopper portion 111 is continuously pressed against the circumferential inner surface of the raised portion 85 of the other circumferential side). The operation screw 93 is rotated until one circumferential edge 116 of the clamp band 87 abuts the stopper 113 and the clamp band 87 is no longer allowed to be diametrically contracted. Here, a circumferential distance (A) between the one circumferential edge 116 of the clamp band 87 and the stopper 113 at start of tightening of the clamp mounting portion 81 by the clamp band 87 (namely, at the time when the inner diameter of the clamp band 87 becomes equal to the outer diameter of the clamp mounting portion 81 as shown in FIG. 10(a)) is equal to or generally equal to a sum of a traveling distance (B) of the rotation stopper portion 111 in one circumferential direction relative to the clamp mounting portion 81 during the time from start to end of tightening of the clamp mounting portion 81 by the clamp band 87 and a traveling distance (C) of the operation screw 93 in the other circumferential direction relative to the clamp mounting portion 81 during the time from start to end of tightening of the clamp mounting portion 81 by the clamp band 87. These travelling distances (B) and (C) are assumed or regarded as equal to each other. When one circumferential edge 116 of the clamp band 87 abuts the stopper 113 (when operation of tightening of the clamp mounting portion 81 is completed), the rotation stopper portion 111 stops at a position before or just before a circumferential inner surface of the raised portion 85 of the one circumferential side. In order to construct in this mode, a circumferential distance between the inner surfaces of the pair of the raised portions 85 is designed longer than the sum of a width of the rotation stopper portion 111 and the travelling distance (B). Meanwhile, the travelling distance (B) may be set a half of the value given by a following formula;

Circumferential distance or flattened length of the clamp band 87 from a center position 118 (refer to FIG. 10(a)) of the band-carrier clamp 89 to the stopper 113—(entire flattened length of clamp band 87—length of an outer periphery of the clamp mounting portion 81 before tightened—circumferential length or flattened length of the clamp band 87 from the other circumferential edge to the center position 118 of the band-carrier clamp 89)

Meanwhile, FIG. 9 is a side view of the another hose with clamp 73, for example, in its state shown in FIG. 10(a).

The stopper 113 may be replaced with a marking such as a colored spot, a dent or a bump that is provided or formed on or in the clamp band 87, at the same position as the stopper 113. And, the clamp band 87 may be constructed so as to be diametrically contracted until the one circumferential edge 116 reaches a position of the marking.

The holding structure of the hose clamp according to the present invention, allows to easily connect a hose to a pipe in a narrow area such as around a fuel tank while securing sufficient sealing property. 

1. A holding structure of a hose clamp wherein the hose clamp has an annular clamp body to be fitted on a clamp mounting portion of an end portion of a hose, the holding structure, comprising: an anti-rotation engaging portion formed on the clamp body, an engaging holder portion provided on the hose so as to engage with the anti-rotation engaging portion in a circumferential direction when the clamp body is fitted on the clamp mounting portion, and wherein the engaging holder portion is provided on an end edge portion of the hose.
 2. The holding structure of the hose clamp as set forth in claim 1, wherein the anti-rotation engaging portion protrudes from the clamp body in a direction toward an end edge of the hose.
 3. The holding structure of the hose clamp as set forth in claim 1, wherein a sealing member or a sealing portion is provided in an inner periphery of the end portion of the hose, the sealing member or the sealing portion is disposed on a longitudinally inner end with respect to the clamp mounting portion.
 4. The holding structure of the hose clamp as set forth in claim 1, wherein the engaging holder portion is in a form of a recess or a cutout in the end edge portion of the hose.
 5. The holding structure of the hose clamp as set forth in claim 4, wherein a beam bridges in the recess or the cutout for preventing the recess or the cutout from being widened.
 6. The holding structure of the hose clamp as set forth in claim 5, wherein the beam is provided in a longitudinally inner end of the recess or the cutout, and the anti-rotation engaging portion engages with a longitudinally outer end of the recess or the cutout when the clamp body is fitted on the clamp mounting portion.
 7. The holding structure of the hose clamp as set forth in claim 5, wherein the anti-rotation engaging portion is designed so as not to contact the beam when the clamp body is diametrically contracted to tighten the clamp mounting portion.
 8. The holding structure of the hose clamp as set forth in claim 1, wherein a protruding portion protruding in a longitudinal direction is formed on an end edge of the hose, and the engaging holder portion is formed in the protruding portion.
 9. A holding structure of a hose clamp wherein the hose clamp has an annular clamp body to be fitted on a clamp mounting portion of an end portion of a hose, the holding structure, comprising: an anti-rotation engaging portion formed on the clamp body, an engaging holder portion provided on the hose so as to engage with the anti-rotation engaging portion in a circumferential direction when the clamp body is fitted on the clamp mounting portion, wherein the clamp body has one circumferential end portion and the other circumferential end portion, and is provided with an operation screw on the other circumferential end portion for diametrically contracting and expanding the clamp body by engaging with the one circumferential end portion or one circumferential end area, the operation screw is arranged so as to extend in a tangential direction or generally in the tangential direction of the clamp body, wherein the engaging holder portion includes a pair of side portions in circumferentially spaced, face-to-face relation to each other, and is formed so as to position the anti-rotation engaging portion in the circumferential direction while receiving the anti-rotation engaging portion movably in the circumferential direction between the pair of the side portions, and wherein a circumferential distance between the pair of the side portions is set so as to locate the anti-rotation engaging portion midway between the pair of the side portions when the clamp body is diametrically contracted to tighten the clamp mounting portion by rotating the operation screw.
 10. The holding structure of the hose clamp as set forth in claim 9, wherein the operation screw has a head and a leading end portion and is arranged with the head being located on a circumferential center side of the clamp body with respect to the leading end portion, and the anti-rotation engaging portion is formed on one circumferential side portion of the clamp body.
 11. The holding structure of the hose clamp as set forth in claim 9, wherein the anti-rotation engaging portion protrudes from the clamp body in an opposite direction of an end edge of the hose.
 12. The holding structure of the hose clamp as set forth in claim 9, wherein the clamp body is in a form of a clamp band, and the clamp band is diametrically contracted or expanded by adjusting an overlapped length or a crossover length of circumferentially opposite end portions or of the one circumferential end area and the other circumferential end area thereof.
 13. The holding structure of the hose clamp as set forth in claim 12, wherein the clamp band is provided on the other circumferential side portion or the other circumferential end area with a stopper or a marking for preventing the clamp band from being diametrically overcontracted, and the clamp band is to be diametrically contracted to tighten the clamp mounting portion by rotating the operation screw until one circumferential edge of the clamp band abuts the stopper or reaches a position of the marking.
 14. The holding structure of the hose clamp as set forth in claim 13, wherein a circumferential distance between the pair of the side portions is set so as to locate the anti-rotation engaging portion midway between the pair of side portions when the one circumferential edge of the clamp band abuts the stopper or reaches the position of the marking. 